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International Journal of Biometeorology
International Journal of Biometeorology
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Abstract: |
Lighting regimes are possibly used as a strategy to improve rabbit production in tropical regions; on this background, this
study was conducted to assess the possible role of different light (L):dark (D) regimes in improving growing New Zealand
white rabbit’s performance. Sixty-four growing rabbits were randomly divided into four groups. Rabbits of the first group
(C) were exposed to 12 h of light (from 10.00 to 22.00 h). Rabbits of the second group (T1) were exposed to 12 h of light
(from 22.00 to 10.00 h). The third group (T2) was exposed to 8 h of light (from 10.00 to 18.00 h), while the fourth group
(T3) was exposed to 8 h of light (from 22.00 to 06.00 h). Temperature-humidity index values ranged between 27.00 and
28.87, indicating exposure of growing rabbits to very severe heat stress. Body weight (BW), body weight gain (BWG),
feed consumption (FC), feed conversion ratio (FCR), carcass traits, blood parameters, and some physiological (rectum
temperature, respiration rate) and health aspects (morbidity, mortality, and health risks %) were investigated. Rabbits of T1
showed the highest (P < 0.05) averages of BWand BWG in comparison with their counterparts. There were no significant
differences in FC; however, rabbits of T1 had the lowest value of FCR at marketing. The percentages of dressed carcass,
liver, and kidney in T1 and T3 were the highest. Non-significant changes were observed among the groups in most of the
metabolic and hematology parameters of blood, except for ALT and N/L ratio. Further, rabbits of T1 showed the lowest
rectal temperature and respiration rate in comparison with their counterparts. Conclusively, the utilization of photoperiod
of afternoon program for over a short period of time in rabbitry brought in beneficial effects on growth performance and
other productive and physiological parameters of growing rabbits.
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